BAXALL CDX 9714 COLOUR VIDEO CAMERA
WHAT OUR EXPERTS SAY...
With so many new and unfamiliar names adorning the sides of CCTV cameras
these days (in some instances no names at all…) the Baxall logo is a
reassuringly familiar sight. In fact if CCTV cameras were cars Baxall's
products would lie somewhere between Volvo and Jaguar in terms of brand
awareness perceived reliability and performance.
Baxall cameras are almost instantly recognisable and no matter what the
spec might be virtually all recent and current models are housed in a
distinctive cream coloured case with a lightly sculptured front and gently
curved edges. This uniformity continues on to the recently launched X-Series.
We've been taking a close look at the CDX9714, one of two models in the range,
the principle difference being the type of power supply. The 9714 is mains
powered (98-260VAC) whilst its stablemate, the CDX9714L/V requires an 11-40 VDC
or 12-30VAC supply.
The key features are above average low-light sensitivity and resolution
plus extensive use of digital signal processing (DSP), which together means the
camera can function in a wide range of conditions including difficult
situations where most regular general purpose models would not be able to cope.
As usual we'll begin the tour with the image sensor and this particular
modes uses a 1/2-inch Sony Exview HAD device with a claimed minimum sensitivity
of 0.4 lux (f1.2). Resolution is towards the high end of the performance range
at 480 lines. Exposure options include an electronic iris, switchable AGC,
configurable backlight compensation, adjustable gamma correction, 4-mode white
balance, auto/manual shutter and connections for an auto-iris lens. There are
some interesting extras too, such as Peak White Inversion (PWI) -- more about
that in a moment -- and 'flickerless' operation, when the camera is used in
some types of tube lighting.
The 9714 has a standard C/CS mounting thread at the front of the case
with back focus adjustment handled by a pair of screws on the top and side of
the case. This is very convenient if, for example, access to one of the screws
is hindered by a wall or ceiling. On the right side of the unit there's
standard square four-pin socket for an auto iris lens and a hinged flap that
opens to reveal three banks of miniature DIP switches, a push button switch for
displaying the backlight compensation 'window' and two rotary presets for
auto-iris lens level and PWI threshold.
DIP switch 1 (SW1) covers AGC (on/off), line-lock phase
(fixed/adjustable), sync (internal/line-lock) and the position and shape of the
backlight compensation window. Three DIP switches provide 8 permutations or
patterns – shown by an opaque window,
temporarily superimposed on the image -- covering the central area, top
and sides of the picture.
DIP switch 2 (SW2) is used to set manual shutter speeds and flickerless
mode; the four switches provide 8 speed settings, from 1/50th sec to 1/10,000th
sec. The first two positions on SW3 are used to set colour balance mode (auto,
fluorescent, indoor & outdoor), position 3 is for gamma correction (normal
0.45/linear 1.0) and the fourth switch enables Peak White Inversion. Briefly,
when PWI is switched on very bright areas of the image are displayed as black.
This can be used to help overcomes exposure problems when using some types of
auto-iris lens, which can react to excessive scene brightness by closing down
resulting in a loss of detail in darker parts of the image.
The backside of the camera is recessed by around a centimetre. This is
very neat touch as it stops the sockets and connectors protruding, reducing the
overall length of the camera when it is installed and at the same time
providing some protection for the connections. Two panel mounted BNC sockets
carry the composite video output and an input for external synch (genlock). A
separate Y/C (S-Video) socket is also provided in the shape of a standard 4-pin
mini DIN connector. A two-way spring terminal carries the connections for a
voltage controlled type auto iris lens and there's a recessed preset for
adjusting line-level phase (when the camera is powered fro an AC source). A
green LED indicator shows power on and the captive main lead emerges from a
collett close to the bottom right hand corner of the back panel.
The top and bottom halves of the case are lightweight but very tough
alloy extrusions; the end caps are plastic mouldings. It's quite busy inside
the case with the shielded mains supply module taking up around a third of the
available space. The absence of a bulky transformer and the wide mains voltage
operating range suggests it is an efficient switched mode type supply and
appears to be confirmed by the fact that there are no hot spots and the camera
body never becomes more that slightly warm to the touch.
There are five other circuit boards inside the case, attached to a steel
sub-frame. The two on the right side are involved with video processing and the
various DSP functions, one at the front – mounted on the back focus adjustment
mechanism supports the CCD image sensor. A board in the base of the camera acts
like a motherboard providing connection to the other PCBs and finally there's
one in the back of the case, which handles the rear panel connections. Overall
it appears to be very well constructed with a minimum of wiring, in fact the
only visible connections are the three mains wires and a ribbon cable from the
image sensor board to the video processor PCB. It's very stable too and the
image never missed a beat when subjected to a healthy dose of the Bench Test
intermittency test, courtesy of the workshop rubber mallet.
SETUP AND OPERATION
In most cases installation should prove relatively painless, mechanically
there are no problems and standard 1/4-inch threaded mounting bosses are built
into the top and bottom panels on the case. The back focus adjustment is quite
smooth; unusually there's no provision for locking the mechanism but this
doesn't appear to be a problem and the setting remains stable and unaffected by
physical shock or vibration.
The only potential trouble spot is likely to be the miniature DIP
switches. They are very small indeed, verging on the microscopic, and quite
deeply recessed so that adjusting them in-situ could pose problems when the
side of the camera is mounted close to a wall. All of the setup operations are
reasonably straightforward and outlined in a fair amount of detail in the
instructions. The booklet is generally well presented though for some reason it
makes no mention of the back panel layout nor will novice installers find much
in the way of explanation for the function and operation of features like gamma
correction or the electronic shutter.
Resolution on our sample is within a whisker of the manufacturer's specs
and in good light the image is packed with fine detail so it would be well
suited to systems using high performance monitors and recording equipment. Low
light performance is good but largely dependent on the AGC being enabled, which
then has an impact on scene brightness and noise levels at higher lighting levels.
There doesn't seem to be a happy medium and some experimentation may be
necessary to get a well-balanced image when there is a wide variation in scene
brightness. Image quality in good light is fine, there's plenty of sharp
detail. Very little noise and colours are crisply defined and natural looking.
The auto colour balance system responds well to change in lighting type though
scenes lit exclusively by tube lighting can have a slightly yellowish tinge,
even when the white balance system is set to fluorescent. The auto iris system
is fairly agile and reacts quickly to sudden changes in scene illumination; the
Peak White Inversion feature looks as though it could have applications over
and above the ones suggested and it could prove useful in locations with areas
of high level lighting, that the backlight compensation facility cannot cope
The CDX9714 slots in neatly between costly
high-performance specialist cameras and the vast majority of mid-range and
general purpose cameras. It's a solid, workmanlike design with enough manual
adjustments to ensure a useable image in al but the most unfavourable
conditions. It's reasonably easy to set up and devoid of any superfluous
gadgetry or the kind of expensive bells and whistles that would rule it out as
uneconomical for marginally difficult installations. Build quality is good and
there's every reason to suppose it will not harm Baxall's well earned
reputation for reliability and longevity. In short a very decent camera, a
useful addition to any system that's capable of making use of its low light
abilities facility to resolve fine detail and definitely worth considering for
moderately tricky jobs.
Design and design features ****
Circuitry and components ****
Ease of installation and wiring ****
Range and variety of functions ****
Accompanying instructions *****
Technical advice and backup ****
Value for money ??
ă R. Maybury